Manual typewriter with means for error correction

ABSTRACT

An error correcting typewriter having a special manual key for operating a type bar carrying a special type font. The type bar is structurally modified so that when actuated it will not advance the carriage. A link connected to the key is adapted to move an inhibitor rod away from the path of movement of a ribbon vibrator allowing maximum movement of the vibrator. Actuation of the key will not result in movement of the carriage but will result in elevation of the lower ribbon portion carrying the obliterating pigment into registration with the type font so that pigment is deposited over a character imprinted in error.

United States Patent [191 Ozimek et al.

[ Feb. 18, 1975 MANUAL TYPEWRITER WITH MEANS FOR ERROR CORRECTION [75]Inventors: Chester E. Ozimek, Park Ridge;

7 Kenneth L. Eldridge, Jr.,

Naperville', both of I11.

[73] Assignee: Sears, Roebuck and Co., Chicago,

22 Filed: Aug. 6, 1973 211 Appl. No.: 386,203

[52] US. Cl 197/181, 197/83, 197/157 [51] Int. Cl B41j 29/36 [58] Fieldof Search 197/91, 154,157,181, 197/83 [56] References Cited UNITEDSTATES PATENTS 3,154,183 10/1964 Wolowitz 197/91 3,204,745 9/1965Wolowitz 197/91 3,666,069 5/1972 Suzuki 197/157 X 3,729,081 4/1973Ozimek et a1 197/181 X 11/1973 Rava et al ..197/181X 3/1974 Davidge eta1 197/82 X Primary Examiner-Edgar S. Burr Assistant ExaminerPaul T.Sewell Attorney, Agent, or Firm-Arnstein, Gluck, Weitzenfeld & Minow [57] ABSTRACT An error correcting typewriter having a special manual keyfor operating a type bar carrying a special type font. The type bar isstructurally modified so that when actuated it will not advance thecarriage. A link connected to the key is adapted to move an inhibitorrod away from the path of movement of a ribbon vibrator allowing maximummovement of the vibrator. Actuation of the key will not result inmovement of the carriage but will result in elevation of the lowerribbon portion carrying the obliterating pigment into registration withthe type font so that pigment is deposited over a character imprinted inerror.

1 Claim, 5 Drawing Figures MANUAL TYPEWRITER WITH MEANS FOR ERRORCORRECTION BACKGROUND OF THE INVENTION The present invention relates toa manual typewriter embodying error correction features adapted for usewith a composite double striped ribbon, one longitudinal half of whichis inked to make character impressions on paper in the usual manner andthe other half of which carries a pressure transferable opaque adherentpigment which when applied over the error renders it substantiallyinvisible so that a correct character may be imprinted thereon.

SUMMARY OF THE INVENTION The typewriter of the present inventionembodies a special key linked to a type bar carrying a universalobliterating type font and having a unique cutout arranged to clear theescapement bale so as not to actuate the escapement system and effectstepwise movement of the carriage. The special key has connected to it alink which is arranged to engage an inhibitor rod and move the same outof the path of travel of a ribbon vibrator arm thus, permitting the armto travel a greater distance so as to align the pigment carrying portionof the ribbon with the type font. The return of the special key to atrest position restores the printing and escapement systems to normaloperating conditions.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view, partlyexploded, showing the cooperative relationship of the various parts ofthe invention in a typewriter.

FIG. 2 is a fragmentary rear perspective view, on an enlarged scale, ofa type bar carrying a universal obliterating type font.

FIG. 3 is a front elevational view of the type bar and obliterating fontillustrated in FIG. 2.

FIG. 4 is a front elevational view, on an enlarged scale, of astructural detail, and

FIG. 5 is a side elevational view, on an enlarged scale, of the detailshown in FIG. 4.

BRIEF DESCRIPTION OF A PREFERRED EMBODIMENT Refering to the drawing, theinvention is shown as applied to a well known make of commercialtypewriter and only those parts of the machine which contribute directlyto the essentials of the present invention have been included in thedrawing. The typewriter, not shown. generally is provided with the usualbank of keys manually operable for imprinting characters, a space bar, aplaten roller and carriage, conventional carriage spacing mechanism, aback space key for producing letter width stepwise movements of thecarriage in a rearward direction, a ribbon field control selector andribbon carrying spools for the ribbon.

Our invention includes the provision of a special key and type font, thekey being preferably located on the right hand side of the bank of keysand operatively connected to mechanism performing particular functions,hereinafter to be described.

Referring to FIG. 1, the typewriter is provided with the usual ribbonvibrator 11 carrying a special ribbon 12, the upper longitudinalone-half of which comprises an inking portion 12a while the lowerlongitudinal onehalf 12b carries a pressure transferable opaque adherentpigment. The vibrator 11 is carried on one end of a crank arm 13 pivotedas at 14 to the frame, with the other arm I6 extending downwardly independing relation to the arm 13. The lower end of the arm 16 isconnected to one end of the link 17, the other end of which is connectedto an arm 18 pivoted on the frame. A link 19 is connected at one end tothe arm 18, the other end of said link being hooked into an elongatedslot 21 provided in the feed arm 22 pivotly supported as at 23 below abracket 24 mounted on the frame. The feed arm 22 includes an integrallateral arm 26 to the distal end of which is connected a link 27, theother end of said link being connected to a universal bar 28 which isadapted to be engaged by each of the conventional key bars, notshown.Each such key bar is connected by a respective link, not shown, to atype bar, each type bar carrying a type font. Normally, when a key isdepressed the conventional type bar, will engage the escapement arch,not shown, soas to actuate-the escapement system and effect stepwisemovement of the carriage, not shown.

A conventional ribbon field control selector lever 34 is pivoted on theframe as at 36 and has its lower end connected as by link 37 to the endof link 19 which is engaged in the slot 21. It will be apparent thatrocking of the lever 34 in a clockwise direction, as viewed in FIG. 1,will shift the hook end 21a of link 19 within the slot 21, substantiallyto the position illustrated in FIG. 1. Rocking of the field selectorlever 34 in a counterclockwise direction will shift the hook end 2la tothe opposite end of slot 21. It will be understood that the hook end 21amay be shifted to an intermediate position in slot 21. It also will beapparent that when the hook end 21a is disposed in the slot 21 in theposition as illustrated in FIG. 1, in relative close proximity to thepivotal axis 23 of the feed arm 22, and the universal bar 28 is causedto be actuated by the depression of a key, the movement transmittedthrough links 19 and 17 to the arm 16 of the ribbon vibrator 11 ismerely sufficient to shift the ribbon 12 to a position where the inkingportion 12a of the ribbon is in registration with the type font. Whenthe hook portion 210 is caused to be moved to the opposite end of theslot 21, remote from the pivotal axis 23, the effective length of arm 22is substantially increased with the result that when the feed arm 22 isrocked by the actuation of a key the movement imparted to the crank arm13 is at a maximum and, accordingly, the ribbon 12 is caused to beshifted so as to present the lower or obliterating portion 12b toregister with the type font.

The degree of shifting of the ribbon 12 by the vibrator 11 is in partcontrolled by an inhibitor rod 38 which extends through an opening in alug 39 mounted on the frame and shaped substantially as shown. As seenclearly in FIGS. 4 and 5, the lug 39 is providedwith a lateral extension41 which is pierced to receive one end of the inhibitor rod 38. Theopposite end of the rod is supported by a bracket 42 supported on theframe. Fixed to the rod 38 is a wire member 43, shaped substantially asshown, and circumposed about rod 38 is a compression spring 44 which isconfined between the bracket 42 and the vertical portion 46 of themember 43. The spring 44 normally tends to urgethe rod 38 to theposition illustrated by the broken lines in FIG. 5 wherein the endportion of rod 38 is disposed directly in the path of travel of the arm16 thereby limiting the pivotal movement of the crank arm 13. The member43 intermediately thereof on the frame, as at 49. The lever 38 includesan extension 51 which is adapted to be engaged by a shoulder portion 52provided in the link 37. Thus, manual movement of the ribbon fieldselector lever 34 will control the positioning of the inhibitor rod 38placing the same either in the retracted position illustrated by thesolid lines, or the extended position, illustrated by the broken linesin FIG. 5. It will be apparent that when the rod 38 is in its normalextended position, as illustrated by the broken lines in FIG. 5, the arm16 is limited in its movement to the left, as viewed in FIG. 4, bycontact with the inhibitor rod 38. Accordingly, arm 16 can move only tothe position illustrated by the solid lines in FIG. 4. thereby movingthe vibrator 11 so that the upper inking portion 12a of the ribbon ispositioned to register with the type fonts thereby to imprintcharacters. When the rod 38 is in retracted position, as illustrated bythe solid lines in FIG. 5, the end of the rod is moved out of the pathof travel of arm 16. Thus, the arm 16 may pivot in a clockwise directionuntil it engages against the shoulder 39a of lug 38. This additionalmovement of the crank arm 13 disposes the lower portion 12b of theribbon to register with a type font when a key is stuck.

the ribbon 12 is incrementally advanced by means of a pivotallysupported pawl 56 provided with a depending finger 57 received in anaperture in the arm 26. The pawl 56 engages with a ratchet wheel 58 onwhich is fixed a ribbon spool supporting disk 59.

The foregoing generally is of conventional construction and ourinvention is related to modification of such construction in order toaccomplish the desired function and results. ln carrying out ourinvention a conventional type bar operatively connected to a selectedkey is modified so as to remove the portion illustrated by the brokenlines and indicated by the letter A. This portion A in the case of theremaining conventional type bars normally is arranged to engage theescapement arch, not shown, to actuate the escapement system to effectstepwise movement of the carriage. Thus, in this instance when the noveltype bar 32 is actuated by depressing key 10, the type bar 32 is causedto rock free from contact with the escapement arch thereby avoidingactuation of the escapement system, with corresponding lack of movementofthe carriage. A special link, generally indicated by the numeral 61and shaped substantially as illustrated by the solid lines in FIG. 1,includes a straight portion 61a, one end of which is received in anaperture provided in the vertical leg 39b of lug 39. The link 61 isprovided with an intermediate U-shaped portion 61b, the bight portion ofwhich is adapted to engage against the vertical leg 46 of the member 43.The link 61 includes a portion 61c, the end of which is connected to thekey bar 29 as at 63. Thus, with the ribbon field selector lever 34disposed in normal printing position, when the special key 10 is depressed, so as to rock the key bar 29 in a counterclockwise direction,as viewed in FIG. 1, the link 61 is drawn to the left so that the bightportion 61b engages the leg 46 and against the force of compressionspring 44 draws the inhibitor rod 38 to the left to assume the positionsubstantially as illustrated by the solid lines in FlG. 5. The endportion of rod 38 now is disposed out of the path of travel of arm 16.Accordingly, the arm 16 now may move to its extreme left position, ashereinbefore described, thereby causing the lower portion of the ribbon12b to move into position for impact by the obliterating font 33,substantially as illustrated in FIG. 2.

The type font 33 includes a generally rectangular impinging surface ofsufficient area to cover the largest of the characters printed by thetypewriter. Preferably, the surface may include a plurality of minutebut closely spaced embossings of any suitable shape which when impingedon the lower ribbon portion 12b will efficiently transfer the opaquepigment over an imprinted error character and thereby obliterate thesame.

OPERATION The operation of the above described embodiment of ourinvention briefly, is as follows:

Assuming that a character has been imprinted in error, in order toeffect a correction, the conventional backspace key, not shown, isdepressed thereby to backspace the carriage, not shown, and locate theerror character in position to be operated upon by the obliterating font33. Upon depression of the special key 10 the type bar 32 is caused toaccelerate towards the carriage to cause the type font 33 to impinge onthe ribbon 12. simultaneously, link 61 draws the end of the inhibitorrod 38 out of the path of travel of the arm 16 so that the crank arm 13may effect maximum movement and elevate the lower ribbon portion 12binto position so that type font 33 may impinge on the portion 12b anddeposit the opaque material carried on the ribbon portion 12b over theerror character thereby obliterating the same. It will be noted that thecarriage has not moved, since the escapement system has not beenactuated. Accordingly, the carriage remains in the same position for thenext printing of a correct character according to conventional practice.

It will be apparent that when the key 10 is released the spring 44causes the inhibitor rod 38 to return to its normal position, asindicated by the broken lines in FIG. 5, wherein the end of the rod isagain disposed in the path of travel of the arm 16 thereby limiting themovement of the arm 16 so that the ribbon portion 12a only is caused tobe moved'to normal printing position.

Various changes coming within the spirit of my invention may suggestthemselves to those skilled in the art; hence I do not wish to belimited to the specific embodiment shown and described or usesmentioned, but intend the same to be merely exemplary the scope of myinvention being limited only by the appended claims.

We claim:

1. In an error correcting typewriter comprising character printingmechanism including printing control keys operatively connected to typebars, paper support mechanism, spacing means including an escapementarch operatively engageable by said type bars for stepwise moving saidpaper support mechanism in a forward direction to accomplish printing aline of characters, a ribbon providing a printing field and a printobliterating field, a pivotally mounted ribbon vibrator having adepending arm and actuated by the printing control keys to guide saidribbon to bring a ribbon field momentarily in impressing position,inhibiting means comprising a slidable member disposed in the path oftravel of said arm to limit the movement of said ribbon vibrator, backspace drive means for stepwise moving said paper support mechanism in abackward direction for moving said slidable member out of the path oftravel of said arm whereby upon actuation of said manual key the ribbonvibrator is caused to elevate the print obliterating field intoimpressing position to be impinged upon by said type font to obliteratea character imprinted in error.

1. In an error correcting typewriter comprising character printingmechanism including printing control keys operatively connected to typebars, paper support mechanism, spacing means including an escapementarch operatively engageable by said type bars for stepwise moving saidpaper support mechanism in a forward direction to accomplish printing aline of characters, a ribbon providing a printing field and a printobliterating field, a pivotally mounted ribbon vibrator having adepending arm and actuated by the printing control keys to guide saidribbon to bring a ribbon field momentarily in impressing position,inhibiting means comprising a slidable member disposed in the path oftravel of said arm to limit the movement of said ribbon vibrator, backspace drive means for stepwise moving said paper support mechanism in abackward direction in letter width increments, the improvement whichcomprises a manually operable key connected to a special type barcarrying a universal obliterating type font, said special type bar beingfree of any engagement with said escapement arch whereby upon actuationof said manual key the paper support mechanism is not moved, a linkoperatively connected to said manual key for moving said slidable memberout of the path of travel of said arm whereby upon actuation of saidmanual key the ribbon vibrator is caused to elevate the printobliterating field into impressing position to be impinged upon by saidtype font to obliterate a character imprinted in error.